Fireworks Exceptional Events -- Event Date: July 4, 2012

Federal regulations (40 Code of Federal Regulations (CFR) Part 50) allow states to exclude air quality data that exceed or violate a National Ambient Air Quality Standard (NAAQS) if it can demonstrate that an "exceptional event" has caused the exceedance or violation. Exceptional events are unusual or naturally occurring events that can affect air quality but are not reasonably controllable or preventable using techniques implemented to attain and maintain the NAAQS. Exceptional events are events for which the normal planning and regulatory process established by the Clean Air Act are not appropriate.

Exceptional events may be caused by human activity that is unlikely to recur at a particular location, or may be due to a natural event. EPA defines a "natural event" as an event in which human activity plays little or no direct causal role to the event in question. For example, a natural event could include such things as high winds, wild fires, and seismic/volcanic activity. In addition, the EPA will allow states to exclude data from regulatory determinations on a case-by-case basis for monitoring stations that measure values that exceed or violate the NAAQS due to emissions from fireworks displays from cultural events. These events can be flagged as being affected by exceptional or natural events and then justified.

Federal regulations (40 CFR Part 50.14 (c)(3)(i)) require that all relevant flagged data, the reasons for the data being flagged, and a demonstration that the flagged data are caused by exceptional events be made available by the State for 30 days of public review and comment. These comments will be considered in the final demonstration of the event that is submitted to EPA. The following monitored values have been attributed to exceptional events:

July 4, 2012, Ogden Monitor Station, 63.7 microg/m³ PM2.5 (Due to Firework Display Emissions)

The documentation to support removing this data from use in regulatory determinations will be available by October 1, 2012, for public review and comment. It can be viewed at the following website www.airquality.utah.gov\Public-Interest\Public-Commen-Hearings\Exceptional_Events\Exceptional_Events.htm or at the DEQ Building located at 150 North 1950 West in Salt Lake City, Utah.

In compliance with the American with Disabilities Act, individuals with special needs (including auxiliary communicative aids and services) should contact Brooke Baker, Office of Human Resources at (801) 536-4412 (TDD 536-4414).

The comment period will close at 5:00 p.m. on October 31, 2012. Comments postmarked on or before that date will be accepted. Comments may be submitted by electronic mail to [email protected] or may be mailed to:

Joel Karmazyn

Utah Division of Air Quality
PO Box 144820
195 N 1950 W
Salt Lake City, UT 84114-4820